Many of you have older houses with porches that have been converted into year-around living spaces. This is a way to increase the livability of your house, but it has some problems in cold weather.

THE DOWNSIDE

Porches almost never have basements. Converted ones have a lot of windows and, often, almost no insulation. They even may not have heating registers.

For this reason, we call them summer, Florida or sun rooms. They are impractical in cold weather. Since a lot of them are houseplant rooms, you'll need to find a new place for your collection over the cold season.

Almost all houseplants have tropical roots, jungles where it never freezes. They've adapted well to our house environments, but they still cannot stand a chill lower than 55 degrees. A week in that cold often is fatal.

Succulents are especially susceptible to cold. So are African violets. Anything less than 65 degrees will murder them.

LOOK FOR SYMPTOMS

The obvious cold signs are easy to spot: Withered leaves, sudden darkening of color and a general listless appearance.

If you catch this early, it's a good idea to moisten everything with water that is slightly warm to the touch. Don't place the pots near heating sources. They may not stand the sudden shock.

Many of us have houseplants in windows to catch the sun. Your room may be warm, but those windows radiate cold. It's a good idea to move them off windowsills in very cold weather.

Plants are a great source of humidity in your house. Your furnace wrings out the moisture in the air, causing dry sinuses and throats. Humidity is valuable in winter. It will make your house seem warmer than it actually is.

Plants will humidify your house, but the dryness increases their need for watering. That's another thing to watch. Your summertime watering schedule will be skewered in cold weather.

Of course, don't over water. Allow the soil tops to dry out. Spraying water on leaves is an excellent idea, except for violets. Spraying will spot their leaves. A pan of water kept near them will increase the humidity.

It's easy to forget about houseplants in winter, until they start looking badly. Remember to protect your friends when the temperature plummets.